1. Field of the Invention
This invention pertains to mechanical devices used in wells such as oil and gas wells. More, particularly, a device is provided for releasing a line supporting a tool in a well from the tool if the tool becomes stuck in the well. A novel release collet mechanism for releasably connecting two members together is also provided.
2. Description of Related Art
A variety of mechanical devices or tools are used in wells, for such purposes as logging the properties of the rock around the well, taking samples of the rock, perforating holes in casing in the well and other purposes. Because of solids accumulating in an open hole or mechanical malfunctions in a cased hole, it may become impossible to retrieve a tool from a well with the line supporting the tool. The line may be a “slick line” or an electric wire line. In this situation it is desirable to release the line from the tool that is lodged in the well.
Different mechanisms have been used for releasing a line from a stuck tool. For example U.S. Pat. No. 5,109,921 discloses a releasable tool with first and second shear pin arrangements. U.S. Pat. No. 5,568,836 discloses a release device having a latch mechanism and a time delay mechanism that is actuated after a time interval has elapsed.